Miniature fans of this kind usually have a square fan housing as depicted in partial section in FIG. 1, and the dimension L (FIG. 1) can be, for example, 20, 25, 30, 40, 50, or 60 mm, so that a fan housing of this kind has sizes from approximately 20×20 mm to approximately 60×60 mm; for known miniature fans, the housing depth T is usually between 8 mm and 25 mm. The 20×20 mm and 25×25 mm sizes are ordinarily referred to as micro-fans or subminiature fans, and the 30×30 to 60×60 mm sizes as miniature fans, the terminology differing by company and by country.
Miniature fans of this kind have become very popular in numerous application sectors, for example in the fields of cooling of circuit boards or the cooling of components in which a high level of power dissipation occurs.